GOV.UK Infrastructure Boosts Security by Migrating to IAM Roles for External Services

The GOV.UK infrastructure team has formally adopted a new security directive, transitioning away from the use of static IAM users and their associated access keys in favor of dynamic IAM roles for both external services and internal applications. This critical decision, published on June 20, 2026, underscores a proactive approach to mitigating security risks inherent in cloud environments. The primary motivation behind this policy change is to eliminate the vulnerabilities posed by long-lived access keys, which, if compromised, can grant unauthorized actors extensive access to sensitive resources. Historically, many services within the GOV.UK ecosystem relied on IAM access keys, inheriting all permissions granted to the respective IAM users. This model presented a significant security challenge, as the leakage or unauthorized reuse of these keys could lead to severe breaches. The new strategy emphasizes the adoption of IAM roles, which establish a trust relationship, allowing external AWS accounts or infrastructure to temporarily assume specific roles with predefined, limited permissions. This mechanism inherently supports the Principle of Least Privilege, ensuring that services and applications only have the necessary permissions for their intended functions, and for the duration they need them. The implementation of this change will be phased, occurring as long-lived access keys are identified as candidates for rotation, as services gain support for assuming IAM roles, and as applications can adopt Kubernetes Pod identities. For internal applications hosted within AWS accounts, the team will prioritize the use of Kubernetes Pod identities or direct IAM role assumption, further reducing reliance on access keys. This systematic migration is expected to reduce the number of access keys requiring management and rotation, thereby streamlining security operations. While this transition promises a more robust security framework, it also introduces operational considerations. Each migration to IAM roles or Pod identities will necessitate additional work in creating and managing the required IAM roles and permission policies. However, the long-term benefits of a reduced attack surface and enhanced compliance with security best practices are expected to outweigh these initial efforts. An example cited is the recent reconfiguration of Fastly to utilize IAM Roles instead of Access Keys, demonstrating the practical application and success of this new approach.